NPD said an average 1.9 million barrels of oil were produced from Norway in December, about 12,000 barrels per day more than in November.
"The oil production is 2 percent below the NPD's prognosis for December and 4 percent below the oil production in December last year," it said in a statement.
Nevertheless, the regulator said oil production in 2013 overall was in line with the NPD's predictions.
It offered no assessment of the production figures.
NPD said Wednesday interest in oil and natural gas areas off the Norwegian coast reached a record level.
"A record number of fields are in operation on the Norwegian shelf," it said. "Discoveries in 2013 offset roughly half of what was produced in the same year."
Last year, there were seven oil and natural gas discoveries in the North Sea, eight in the Norwegian Sea and five in the Barents Sea.
Combined, the new discoveries amount to as much as 666 million barrels of oil and as much as 2 trillion cubic feet of natural gas, NPD said.
Norway is one of the leading oil and natural gas producers in Europe.